<html>

<head>
    <style type="text/css">
        #selectNum button {
            transition: height 2s;
        }
    </style>


    <script src="19.js">
        </script>
</head>

<body onload="load()">
    <div id="operation">
        <input type="text" id="input">
        <button id="add">add</button>
        <button id="sort">sort</button>
    </div>
    <div id="selectNum">

    </div>
</body>

</html>